CXD1185CQ/CR
Appendix C
Changes from CXD1185AQ
The CXD1185CQ is pin compatible and comes in the same package as its predecessor, CXD1185AQ. The
CXD1185C has the identical electrical characteristics as the CXD1185AQ. This appendix summarizes the new
functions of CXD1185C.
New features
•
•
Single initiator mode detection
Selection phase SCSI parity check/ignore switch
Single initiator mode detection
The CXD1185AQ did not support single initiator mode. It was able to be selected under single initiator mode,
but since it returned “0” for the value of SID2-0, it was impossible to tell whether it was selected by ...
a. a SCSI device with ID “0” in multiple initiator environment or
b. the sole initiator in single initiator environment.
The CXD1185C has a new register bit “Single initiator MODe” flag to solve the problem.
SMOD
Single initiator MODe Flag
Register SCSI ID register (06 h)
Bit bit4 (Read Only)
SMOD
description
0
1
SID value VALID (Selected in multi initiator environment)
SID value INVALID (Selected in single initiator environment)
This flag is updated during every selection phase.
NOTE! With this flag, the CXD1185C supports single initiator in target mode. The CXD1185C still does not
support execution of single initiator mode selection. Therefore, this new feature has no significance to
users who wishes to use the CXD1185C as initiator.
Software changes
initiator Not required
target
It is now possible to separate the task after the selection for single initiator environment and multi
initiator environment.
SCSI parity check/ignore switch
The CXD1185AQ always responded to selection when selection/reselection was enabled. The CXD1185C
has an option not to respond to selection when there is SCSI parity error.
SSPE
Selection SCSI Parity Enable
Register MODE register (0C h)
Bit bit4 (R/W)
SSPE
description
0
1
Respond to selection even when SCSI parity error is ignored
Does not respond to selection when there is SCSI parity error
Initiators that does not implement the reselection phase and do not operate in multiple initiator environment are allowed to set only the
target’s SCSI bit during selection phase.
—33—
SONY [ SONY CORPORATION ]
